As it stands, we are able to produce green hydrogen, but production is tiny. In order for it to become a viable alternative to fossil fuels, a massive scale-up is needed.
The electrolyzer turns the seawater into four main substances: hydrogen gas, oxygen gas, an acid stream, and an alkaline slurry that consists of calcium and magnesium-based materials.
It is the alkaline slurry that is important when it comes to carbon sequestration: when exposed to air, the alkaline slurry pulls out the CO2 and traps it, ready to be discharged into the sea.
There has been a lot of buzz recently around LA-based start-up Equatic, which claims to have built a machine that can store carbon in the ocean while at the same time producing green hydrogen.
An electrolyzer is basically a machine that splits water into hydrogen and oxygen. In the case of Equatic, it runs on clean electricity, such as that produced by wind, solar, or hydro.
The process of the Equatic machine is complex, but in a nutshell, it works as follows. Firstly, it pumps seawater into an electrolyzer.
When it comes to tackling climate change, in particular rising temperatures, many scientists believe that it will be necessary to capture and store more of the Earth’s excess carbon.
Experts have made various proposals on how to do this, including sequestering the carbon and injecting it into rocks far below the Earth’s surface.
One option of particular interest is how the ocean can be used to capture and store carbon in the long term. Indeed, the ocean already absorbs an estimated 25% of carbon emissions.
A separate but equally important challenge when it comes to climate change is how to produce green hydrogen on a large enough scale that it can replace fossil fuels.
In early 2023, it started operating two pilot plants from barges in Singapore and Los Angeles. Each machine removes around 30-40 tons of CO2 per year (that is equivalent to the annual emissions of around eight cars).
It is now focusing on constructing a machine that will be the world’s largest ocean-based CO2 removal plant. The machine will be based in Singapore.
Sources suggest that the new machine will be 100 times larger than the pilots and that it will remove around 4,000 tons of CO2 from the atmosphere per year.
At the same time, it is expected to produce around 100 tons of hydrogen per year. Not everyone agrees that scaling these machines is a good idea, however.
As it stands, the Equatic project is small. However, the company has plans to scale and they are already underway.
In the last step, the acid waste stream produced by the electrolyzer is neutralized (so as not to acidify the ocean) and is discharged into the sea as well.
The CO2 that is captured by the Equatic machine ends up in the ocean as dissolved bicarbonate ions and solid mineral carbonates.
In these forms, it is immobilized for 10,000 years and billions of years respectively. Unless heated to very high temperatures of around 900°C, the CO2 will not be released.
It seems, then, that Equatic and other similar companies have a few hurdles to clear when it comes to convincing both experts and non-experts of the benefits of their technology.
Only time will tell whether this technology will eventually offer a viable solution to two of the main climate challenges: carbon storage and green hydrogen production.
Sources: (BBC)
See also: How to reduce your carbon footprint while saving money
Many skeptics are worried that we do not have enough evidence that there will be a good enough return on the investment.
Couple this with the strict regulatory frameworks they must adhere to and marine carbon storage companies will have their hands full over the next few years.
There is also the more general concern that focusing on ocean-based carbon removal does nothing to address the root cause of the climate crisis.
Indeed, it could be argued that instead of solving the problem, this would give the illusion of a quick fix, which would only delay the process of finding a real solution to the problem of climate change.
Another key concern is about the viability of marine carbon removal and whether it will actually make enough of a difference.
Many experts have expressed concerns about ocean-based carbon storage, in particular about how it may impact the surrounding marine ecosystems.
There are concerns, for example, that ocean-based carbon storage machines could alter the ocean chemistry, which in turn could cause changes in nutrient levels and species abundance.
Indeed, the scaling of ocean-based carbon removal technology will require a huge investment in infrastructure, equipment, and operations.
When it comes to the climate crisis, there are many key issues that need to be addressed. High on the list is identifying a fuel source that offers a realistic and viable alternative to fossil fuels and working out what to do about carbon emissions. Until recently, no innovation has offered a solution that would resolve both of these issues. However, the Los Angeles-based company Equatic has come up with an ocean-based carbon removal machine that they claim is simultaneously able to store carbon and produce hydrogen. Not everyone is on board with the proposed solution, however.
Curious? Check out this gallery to find out more.
Understanding carbon capture and sequestration technology
Could marine carbon removal be the future?
LIFESTYLE Climate change
When it comes to the climate crisis, there are many key issues that need to be addressed. High on the list is identifying a fuel source that offers a realistic and viable alternative to fossil fuels and working out what to do about carbon emissions. Until recently, no innovation has offered a solution that would resolve both of these issues. However, the Los Angeles-based company Equatic has come up with an ocean-based carbon removal machine that they claim is simultaneously able to store carbon and produce hydrogen. Not everyone is on board with the proposed solution, however.
Curious? Check out this gallery to find out more.